DK2823790T3

DK2823790T3 - TWO PARTICULAR ARTICLE LED SPACES AND PROCEDURE FOR PREPARING SAME

Info

Publication number: DK2823790T3
Application number: DK14174481.3T
Authority: DK
Inventors: Hieng Kim
Original assignee: Heraeus Medical Gmbh
Priority date: 2013-07-08
Filing date: 2014-06-26
Publication date: 2017-07-24
Also published as: US20150012105A1; CA2855302C; DE102013011296A1; AU2014203507B2; CN104274260A; EP2823790A1; JP5882406B2; US9931217B2; CN104274260B; JP2015016330A; EP2823790B1; CA2855302A1; AU2014203507A1; ES2633978T3

Description

Two-part articulating joint spacer and method for producing the same

The invention relates to an articulating joint spacer for the temporary replacement of a joint, wherein the joint spacer comprises two spacer parts, each of which has a sliding surface, on which the spacer parts abut one another movably in the patient-inserted state, and roll over one another. Further the invention relates to a method for producing a two-part articulating joint spacer.

Joint endoprostheses currently have a service life of several years. However, undesirable loosening of the articular endoprostheses, may occur before the standard service lives are reached. Septic and aseptic loosening are differentiated from one another. Microbial germs can not be detected in the case of aseptic loosening. The causes of aseptic loosening may be manifold. Frequently, aseptic loosening is attributable to abrasion on the sliding surfaces of the joint endoprostheses. In the case of septic loosening, the loosening process is caused by microbial germs. One distinguishes between early and late infections depending on the temporal occurrence. The septic loosening is a very serious disease for the patient, which is additionally associated with very high costs. Both aseptic and septic loosening usually require revision. A distinction is made between single-stage and two-stage revisions. In the case of septic loosening, very frequent revisions are made.

In the case of two-stage revisions, the infected joint endoprosthesis is removed in a first operation (OP), debridement (removal of the infected tissue) takes place, and a temporary spacer, a so-called distance spacer, is subsequently used. This spacer fills the space of the previously revised endoprosthesis for a few weeks until the present infection has subsided. This spacer function is very important in order to prevent atrophy of the muscles during this period and to stabilize the resection situation. A distinction is made between non-articulating and articulating spacers. Articulating spacers or joint spacers reproduce the joint function and allow a certain mobility of the affected limbs. It is therefore possible to mobilize patients at an early stage. Today, articulating spacers represent the state of the art. The spacer is removed in a second operation, debrided again, and then a cemented or cement-free revision joint endoprosthesis is implanted.

There are antibiotics-equipped spacers for the temporary replacement of knee, hip and shoulder joint endoprostheses on the market. Such spacers are known, for example, from US 2010/042214 A1 and US 2011/015754 A1. The spacers described therein contain hollow spaces from which the antibiotics are released. The uneven release of active EP 2823790 ngredient is disadvantageous. Alternatively, for example, DE 10 2007 004 968 B4 and WO 2011 086788 A1 also propose bone cements from which the antibiotics are soluble. When such bone cements are used for the preparation of a spacer, the antibiotics are released directly at the site of the infection over an extended period of time and must therefore be soluble from the material of the spacer. Such a spacer made of bone cement is proposed, or example, in the patent application US 2012/026156 A1. US 6 361 731 B1 discloses a spacer mold which may be filled with a bone cement to produce a spacer, as well as an articulating joint spacer according to the preamble of claim 1.

Spacers are often produced by the surgeons themselves from conventional aolymethyl methacrylate bone cements (PMMA bone cements) using suitable casting nolds. In this case, one or more antibiotics are admixed to the PMMA bone cement aowder before the spacer preparation. In addition, zirconium oxide powders may also be ntroduced or applied as a radiopaquer, which serves as a contrast medium for X-ray ixaminations, as proposed, for example, in DE 103 40 800 A1 or FR 2 821 751 A1. A disadvantage of such spacers is that the antibiotic-containing spacers wear with he zirconium oxide powder on the sliding surfaces. This has the disadvantage that the sliding surfaces may be impaired under mechanical loading. Particularly in the case of articulating spacers, in which the sliding surfaces of the spacers roll over each other, abrasion may occur. Such abrasion may lead to inflammation which has a detrimental affect on healing.

The object of the invention is therefore to overcome the disadvantages of the prior art. In particular, a spacer according to the invention and a method according to the nvention are intended to provide a possibility for preventing the abrasion and, in a simple manner, to create a surface which is as even, stable and robust as possible, and which allows problem-free movement of the spacer so produced without causing any deterioration in the mobility of the joint, impairment of the healing, or pain in the patient due o abrasion on the articulating sliding surfaces of the spacer. The device and the method should be as universal as possible.

The object of the invention is achieved by an articulating joint spacer for the emporary replacement of a joint, wherein the joint spacer comprises two spacer parts 3ach having a sliding surface on which the spacer parts movably abut and roll over one another when inserted in the patient, wherein the sliding surfaces are formed from a first ow -abrasion bone cement while the remaining spacer parts are at least partially formed EP 2823790 rom a second bone cement which is different in comparison to the first bone cement, and vhich contains a water-soluble antibiotic, wherein the first bone cement in the region of the iliding surfaces has a thickness of at least 1 mm on the second bone cement.

Both bone cements are preferably polymethyl methacrylate bone cements.

It may be provided that the first bone cement is arranged in the region of the iliding surfaces with a thickness between 2 mm and 15 mm, particularly preferably with a hickness between 6 mm and 11 mm.

These thicknesses are sufficient to ensure good stability of the sliding surfaces ormed by the first bone cement.

Furthermore, provision may be made for the first bone cement to have at least one inchoring which continues conically from the direction of the sliding surface into the emaining spacer parts, in particular into the second bone cement.

This results in a more stable bonding of the two bone cements. In addition, the imount of cement containing expensive antibiotics used may be reduced.

With a further development of the invention, it is proposed that the remaining ipacer parts and at least the bonding of the joint spacer to the bone of the patient should consist entirely of the second bone cement, while the regions of the joint heads of the joint ipacer, which are spaced apart from the sliding surface, should also preferably consist of he second bone cement, more preferably the regions of the joint heads of the joint spacer, vhich are spaced apart from the sliding surface by at least 1 mm, should consist of the iecond bone cement.

This ensures that the structure of the joint spacer is as simple as possible. In iddition, as large as possible parts of the surface, which do not belong to the claimed iliding surface of the spacer parts, may be used for the release of antibiotics.

The antibiotic in the second bone cement is preferably selected from the groups of iminoglycoside antibiotics, glycopeptide antibiotics, lincosamide antibiotics, quinolone intibiotics, oxazolidinone antibiotics, gyrase inhibitors, carbapenemes, cyclic lipopeptides, llycylcycline and peptide antibiotics.

According to a particularly preferred embodiment, the antibiotic is selected from he group consisting of gentamicin, tobramycin, amikacin, vancomycin, teicoplanin, lalbavancine, lincosamine, clindamycin, moxifloxacin, levofloxacin, ofloxacin, ciprofloxacin, neropenem, tigecycline, linezolid, eperezolid, ramoplanin, metronidazole, tinidazole, »midazole and colistin, and salts and esters thereof. EP 2823790

Accordingly, the at least one antibiotic may be selected from the group consisting of gentamicin sulfate, gentamicin hydrochloride, amikacine sulfate, amikacin hydrochloride, tobramycin sulfate, tobramycin hydrochloride, clindamycin hydrochloride, lincosamine hydrochloride and moxifloxacin.

According to the invention, it is particularly preferred if the low-abrasion first bone cement comprises a radiopaque powder with a Mohs hardness of less than 8, preferably a Mohs hardness of less than 6, particularly preferably a Mohs hardness of less than 4.

The lower the hardness of the radiopaque powder of the first bone cement, the less it contributes to the abrasion of the sliding surfaces.

It is particularly preferred that the hardness of the radiopaque powder in the first bone cement is matched to the hardness of the remaining first bone cement, preferably the difference in the Mohs hardness of the components is less than 2, particularly preferably less than 1. When the hardness of the radiopaque powder is matched to the hardness of the other solid component or the other solid components, the abrasion of the sliding surfaces is significantly reduced.

It may also be provided that the second bone cement contains a mixture of at least two antibiotics, preferably selected from gentamicin, vancomycin and clindamycin.

Such mixtures are particularly suitable for the treatment of infections on the joint.

Furthermore, it may be provided that the interior of the spacer parts consists of the first bone cement.

By means of this measure, the amount of the second bone cement used may be reduced, which, on the one hand, saves costs, and, on the other hand, avoids the unnecessary use of antibiotics.

According to a particularly preferred embodiment of the invention, the free surface of the first bone cement is coated with at least one antibiotic.

This surface may also help to combat the infection immediately after its onset.

According to a preferred embodiment of the invention, it may be provided that the low-abrasion first bone cement comprises a calcium carbonate powder and/or barium carbonate powder.

The calcium carbonate powder and the barium carbonate powder comprise, on the one hand, the desired radiopaque properties so that the spacer generates the desired contrast in the case of an x-ray image. At the same time, however, the hardness of these EP 2823790 powders is lower than that of zirconium oxide powders, so that abrasion on the sliding surfaces is reduced.

According to the invention, it may also be provided that the free surface of the first bone cement is coated with at least one antibiotic.

It is particularly preferred that the two-part joint spacer is an articulating knee spacer.

The objects of the invention are also achieved by means of a set for the build-up of such a joint spacer comprising a cartridge and/or an application system containing the pasty low-abrasion first bone cement or comprising a second cartridge system and/or a second mixing system containing the starting components for the first low-abrasion bone cement, comprising a second cartridge and/or a second application system containing the second antibiotic-containing bone cement or comprising a cartridge system and/or a mixing system containing the starting components for the second antibiotic-containing bone cement ,and having at least two spacer molds for the production of a molded part from the first low-abrasion bone cement, wherein the inner surfaces of the spacer molds are a negative image of the sliding surfaces to be produced.

Similarly, the objects of the invention may also be achieved by a set for the buildup of such an articulating spacer, comprising at least two spacer components, which consist of the first bone cement, and wherein each comprises a sliding surface of the spacer, and having a cartridge and/or an application system containing the second antibiotic-containing bone cement or comprising a cartridge system and/or mixing system containing the starting components for the second antibiotic-containing, bone cement.

Such sets are easy to use and, at the same time, provide the user with an individual treatment for the patient. For example, an individual and particularly suitable antibiotic mixture for the second bone cement may be used. It is also conceivable that a particularly suitable spacer mold may be selected from a plurality of different spacer molds and spacer sizes in order to fit particularly well with the anatomy of the patient or with the treatment situation, in particular the individual adaptation of the infection treatment (degree of debridement only visible during the operation process).

The objects of the invention are further achieved by a method for producing a two-part articulating joint spacer in which a sliding surface is formed from a low-abrasion first bone cement in both spacer parts and at least the surfaces of the remaining spacer parts are at least 50% bone cement containing at least one water-soluble antibiotic, wherein the EP 2823790 first bone cement is arranged in the region of the sliding surfaces with a thickness of at least 1 mm on the second bone cement.

Preferably, it may be provided that the second bone cement is produced with an antibiotic or a mixture of different antibiotics, preferably selected from gentamicin, vancomycin and clindamycin.

Such mixtures are particularly suitable for the treatment of infections on the joint. With a further development of the method according to the invention, it is proposed that a radiopaque powder with a Mohs hardness of less than 8 be blended into the first bone cement, preferably a Mohs hardness of less than 6, more preferably a Mohs hardness of less than 4, in particular calcium carbonate powder and barium carbonate powder.

With a preferred further development of the method, it is proposed that first the second bone cement is molded and then the first bone cement is applied to the second bone cement and the sliding surfaces are formed.

Alternatively, it may be provided that the first bone cement is first filled in a spacer mold, wherein the sliding surface is formed by a negative mold of the inner side of the spacer mold and then the second bone cement is applied to the first bone cement and the remaining surface of the spacer parts is formed. According to the invention, it may preferably be provided that the remaining surface of the spacer parts is formed a negative image of the spacer form. Alternatively or additionally, it may also be provided that the cured spacer parts are attached to the bone with the second bone cement.

These methods are suitable for simple implementation in the often hectic environment of an OP.

The invention is based on the surprising finding that the use of two bone cements succeeds in producing a more stable running surface or sliding surface of the articulating spacer parts without the advantages of an antibiotic-releasing spacer being lost. The spacer produced in this manner leads to fewer problems during its use.

Exemplary embodiments of the invention are explained below with reference to a schematically illustrated figure, without, however, limiting the invention.

Fig. 1 shows a schematic cross-sectional view of a spacer according to the invention, which is produced from two bone cements (6, 7, 12, 13). The spacer shown is a two-part articulatory knee spacer which is provided for the temporary replacement of a EP 2823790 knee joint. A plane of the artificial knee joint parallel to the sagittal plane is selected as the sectional plane shown.

The two parts of the knee spacer are a tibial part 1 (in the lower part in Fig. 1) and a femoral part 2 (in Fig. 1 top). The tibial part 1 is attached to a tibial bone 4 of a patient. The tibial part 1 has a joint head with a joint socket. The joint head is produced from a first bone cement 6, which has a sufficient hardness to avoid abrasion by using barium carbonate powder and/or calcium carbonate powder as a radiopaquer and, optionally, may contain antibiotics 1, or be antibiotic-containing. The first bone cement 6 is thus low-abrasion. The remaining tibial part 1 is made of a second bone cement 7, which contains a mixture of two water-soluble antibiotics which are adapted to the patient's treatment situation.

The joint head is anchored in the tibial bone 4 via a conical pin 8. As a result, a stable connection of the tibial part 1 with the bone 4 is achieved and the amount of antibiotics used in the second bone cement 7 is reduced, and antibiotics are thereby saved. In addition, further anchorings 8 from the second bone cement 7 are anchored in matching conical recesses in the tibial bone 4 in order to achieve a more stable connection of the tibial part 1 of the spacer to the tibial bone 4.

The femoral part 2 of the spacer is constructed in the same way. On the femoral bone 10 of a patient, a joint head is formed from a low-abrasion bone cement 12, and is fastened with an antibiotic-containing second bone cement 13. The first bone cement 12 of the femoral part 2 of the spacer is preferably the same as the first bone cement 6 of the tibial part 1 of the spacer, while the second bone cement 13 of the femoral part 2 of the spacer is preferably the same as the second bone cement 7 of the tibial part 1 of the spacer. A stable connection of the joint head to the femoral bone 10 is achieved with the aid of a conical anchoring 14.

Apart from the joint heads, the surfaces of the two spacer parts 1, 2 are implemented with the second bone cement 7, 13 and may therefore release antibiotics when inserted in the patient, in particular in the direction of the bones 4, 10 of the patient.

The two spacer parts 1, 2 are in contact with each other in the intended state, i.e. when inserted in the patient, as shown in Fig. 1, via the joint heads.

For this purpose, sliding surfaces 16, 18 are provided on the surfaces of the joint heads, similar to a natural knee joint, by means of which the two spacer parts 1, 2 may roll EP 2823790 over the other or slide over the other. As a result, articulation of the spacer parts 1, 2 and thus the reproduction of the mode of operation of the knee is possible.

Since the sliding surfaces 16, 18 are made from the first low-abrasion bone cement 6, 12, the sliding surfaces 16, 18 remain intact during the residence time of the temporary knee paste, so that no (or very few) particles detach from the sliding surfaces 16, 18. As a result, the mobility of the joint spacer is maintained and there is no impairment of the healing by abrasion.

At the same time, the antibiotic mixture from the second bone cement 7, 13 of the two spacer parts 1,2 is continually released in order to support the healing and is available for combating infections.

The example shown relates to a knee spacer which is preferred according to the invention. The invention, however, is not limited to knee spacers, but also relates to all other forms of second temporal joint spacers such as, for example, elbow spacers, hip joint spacers, ankle joints or shoulder joint spacers. For the person skilled in the art, the example of a spacer for a knee described in Fig. 1 may be easily applied to spacers for other joints.

The features of the invention disclosed in the foregoing description, as well as the claims, figures and embodiments, may be essential both individually and in any combination for the implementation of the invention in its various embodiments, wherein the scope of the invention is defined solely by the claims. EP 2823790

List of reference numerals 1 Spacer part/tibial part 2 Spacer part/femoral part 4 Bones (tibial part) 6 Low-abrasion bone cement (tibial part) 7 Antibiotics-containing cement (tibial part) 8 Anchoring 10 Bones (femur) 12 Low-abrasion bone cement (femoral part) 13 Antibiotics-containing cement (femoral part) 14 Anchoring 16 Sliding surface (tibial part) 18 Sliding surface (femoral part) EP 2823790

Claims

TWO PARTICULAR ARTICLE LED SPACES AND PROCEDURE FOR PREPARING SAME

An articulating articulated spacer for the temporary replacement of an articulation, wherein the articulated spacer comprises two spacer portions (1, 2), each comprising one sliding surface (16, 18), the spacer portions (1,2), in the patient-inserted condition, touching each other in a mobile manner and rolling off one another, characterized in that the sliding surfaces (16, 18) are made of a wear-poor first bone cement (6, 12) and the remaining spacer parts (1, 2), at least in part, is made of a second bone cement (7, 13) which is different from the first bone cement, wherein the second bone cement contains one water-soluble antibiotic, wherein the first bone cement (6, 12) is placed on the second bone cement (7, 13) in the area of the sliding surfaces (16, 18) with a thickness of at least 1 mm.

Spacer according to claim 1, characterized in that the first bone cement (6, 12) is arranged on the second bone cement in the area of the sliding surfaces (16, 18) having a thickness of between 2 mm and 15 mm, particularly preferably placed with a thickness between 6 and 11 mm.

Spacer according to claim 1 or 2, characterized in that the first bone cement (6, 12) comprises at least one anchorage (8, 14) which proceeds conically from the direction of the sliding surface (16, 18) into the remaining spacer. parts (1, 2), in particular into the second bone cement (7,13).

Spacer according to one of the preceding claims, characterized in that the remaining spacer parts (1, 2) consist entirely of the second bone cement (7, 13) and at least the joints of the joint spacer to the bone (4, 10). the patient consists of the second bone cement (7, 13), preferably the areas with the joint heads (6, 12) of the joint spacer disposed at a distance from the sliding surface (16, 18) also consist of the second bone cement (7). , 13), in particular preferably that the areas with the articulated heads (6, 12) of the articulated spacer spaced at least 1 mm from the sliding surface (16, 18) consist of the second bone cement (7, 13). .

Spacer according to one of the preceding claims, characterized in that the wear-poor first bone cement (6, 12) contains an X-ray powder with a Mohs hardness of less than 8, preferably a Mohs hardness of less than 6, especially preferably a Mohs hardness. of less than 4. EP 2823790

Spacer according to one of the preceding claims, characterized in that the second bone cement (7, 13) contains a mixture of at least two antibiotics, preferably selected from gentamicin, vancimycin and clindamycin.

Spacer according to one of the preceding claims, characterized in that the free surface of the first bone cement is coated with at least one antibiotic.

Spacer according to one of the preceding claims, characterized in that the wear-poor first bone cement (6, 12) contains a calcium carbonate powder and / or a base of carbonate powder.

A kit for constructing an articulating spacer according to any one of the preceding claims, comprising a cartridge and / or an application system containing a pastrous abrasion-resistant first bone cement (6, 12), or comprising a second cartridge system and / or a second a mixing system containing the starting components of the wear-poor first bone cement (6, 12) comprising a second cartridge and / or another application system containing the antibiotic-containing second bone cement (7, 13), or comprising a cartridge system and / or a mixing system containing the starting components for the second bone cement (7, 13i) of the antibiotic, and at least two spacer molds for making a mold part out of the wear-poor first bone cement (6, 12), the inner surfaces of the spacer molds comprising a negative image of the sliding surfaces (16, 18) to be manufactured.

A kit for constructing an articulating spacer according to one of claims 1 to 8, comprising at least two spacer components consisting of the first bone cement (6,12), each comprising one sliding surface (16, 18) of the spacer, comprising a cartridge and / or an application system comprising the antibiotic-containing second bone cement (7, 13), or comprising a cartridge system and / or mixing system comprising the starting components of the antibiotic-containing second bone cement (7, 13).

A method of producing a two-piece articulating articulated spacer, wherein a sliding surface (16, 18) of both spacer portions (1, 2) is formed from a wear-poor first bone cement (6, 12), and wherein at least the surfaces of the remaining spacer portions (1, 2) are formed with a second bone cement (7, 13) different from the first bone cement, at least at a level of 50% containing at least one water-soluble antibiotic, wherein the first bone cement (6, 12) is applied to the second bone cement (7, 13) in the area of the sliding surfaces (16, 18) at least 1 mm thick. EP 2823790

Process according to claim 11, characterized in that the second bone cement (7, 13) is prepared with an antibiotic or a mixture of different antibiotics, preferably selected from gentamicin, vancimycin and clindamycin.

Method according to claim 11 or 12, characterized in that an X-ray powder with a Mohs hardness of less than 8, preferably with a Mohs hardness of less than 6, especially preferably with a Mohs hardness of less than 4, in particular calcium carbonate powder and / or barium carbonate powder, the first bone cement (6, 12) is added.

Method according to claims 11 to 13, characterized in that the second bone cement (7, 13) is formed first, after which the first bone cement (6, 12) is applied to the second bone cement (7, 13) and the sliding surfaces (16). , 18) are designed.

Method according to claims 11 to 13, characterized in that the first bone cement (6, 12) is filled into a spacer mold first, where the sliding surface (16, 18) is formed via a negative image of the inside of the spacer mold, and whereafter the second bone cement is applied to the first bone cement and the remaining surface of the spacer parts (1,2) is formed, preferably formed via a negative form of the spacer shape, and / or the cured spacer parts (1,2) are fixed. to the bone (4,10) by means of the second bone cement (7, 13). EP 2823790